This invention relates generally to electrochemical cells. In some specific embodiments, the invention relates to high-temperature, rechargeable electrochemical cells, and related devices.
Metal halide electrochemical cells (for example, sodium-metal chloride batteries) including a molten metal negative electrode (usually referred to as the anode) and a beta-alumina solid electrolyte, are of considerable interest for energy storage applications. In addition to the anode, the cells include a positive electrode (usually referred to as the cathode) that supplies/receives electrons during the charge/discharge of the cells. In some designs, the cathode volume is cylindrical, with the axis of the cylinder in the longitudinal direction. The cathode composition typically includes a porous interspersed mixture of electroactive metal and alkali metal halide powders, impregnated with molten electrolyte. The electrochemical cell further includes a positive current collector (usually referred to as the cathode current collector). The cathode current collector typically includes a solid or composite nickel rod/wire that extends into the cathode composition. In these electrochemical cell configurations, the electronic cathode current is conducted radially through the porous metal network and axially through the cathode current collector.
Metal halide electrochemical cells (for example, sodium-metal chloride batteries) including a molten metal negative electrode (usually referred to as the anode) and a beta-alumina solid electrolyte, are of considerable interest for energy storage applications. In addition to the anode, the cell include a positive electrode (usually referred to as the cathode) that supplies/receives electrons during the charge/discharge of the cells. The cathode typically includes a porous metal network interspersed with the cathode composition and impregnated with molten electrolyte. The electrochemical cell further includes a positive current collector (usually referred to as the cathode current collector). The cathode current collector typically includes a solid/plated nickel rod/wire that extends into the cathode composition. In these electrochemical cell configurations, the electrical current is conducted radially through the porous metal network and axially through the cathode current collector.
However, the electrochemical cell configurations with the conventional cathode current collector designs may be cost-prohibitive in some end-use applications. Further, the electrochemical cells (such, as sodium metal halide batteries) may, under some conditions, degrade very rapidly, and the charging time may increase significantly. Thus, there is a need for cost-effective electrochemical cells having the desired performance attributes for a variety of different applications.